6

I'm using QGIS for quite a while now but I'm having some problems in measuring the volume of a depression zoned North of a waste dump I'm studying.

For the analysis I'm using a recent 1mx1m DTM of the area:

enter image description here

As I said the main element of the study is an estimation of the volume of the depression North of the dump. Here's the hillside of the area:

enter image description here

where I highlighted the boundaries of the depression.

As tool for the estimation I used the SAGA GIS tool Raster Volume in Qgis.

As Input GRID information I used the 1mx1m DTM but after running it on the log message panel here's the result:

Usage: saga_cmd grid_calculus 2 [-GRID <str>] [-METHOD <str>] [-LEVEL <str>]
            -GRID:<str>     Grid
            Grid (input)
            -METHOD:<str>   Method
            Choice
            Available Choices:
            [0] Count Only Above Base Level
            [1] Count Only Below Base Level
            [2] Subtract Volumes Below Base Level
            [3] Add Volumes Below Base Level
            Default: 0
            -LEVEL:<str>    Base Level
            Floating point
            Default: 0.000000*  

I used the "Count only above base level" method considering the lowest point of the DTM as base level, but as you can see the result is a 0 value volume.

Am I mistaking anything? Here is the .asc DTM.

  • I don't find any evidence to the sentence "[...] but as you can see the result is a 0 value volume". Where do you get this result? – mgri Feb 19 '17 at 14:29
  • The result appears in the log messages panel after running SAGA tool raster volume. The result should look like this: gis.stackexchange.com/questions/176374/…. But no numeric result is returned.. – Mirko Feb 19 '17 at 14:35
  • I get this result: Grid Volume: Volume: 890177920.097229. Did you get a 0 value, instead? – mgri Feb 19 '17 at 14:45
  • I actually didn't get any result at the end of the process. I think the processing of algorithm fails.. Could you send me the log? – Mirko Feb 19 '17 at 14:53
  • I post it as an answer since I can't paste it here. – mgri Feb 19 '17 at 14:55
5

Using QGIS 2.18.3, it seems to work fine.

I set the "County Only Above Base Level", with base level equals to 0 and I get this log:

Algorithm Raster volume starting...
grid_calculus "Grid Volume" -GRID "C:\Users\xxxxx\AppData\Local\Temp\processingdd38dbc0f5ec434f922835f11ed2d9d0\3ddfa5d81c1744819d54de14d3c7a8f1\DTMdiscarica.sgrd" -METHOD 0 -LEVEL 0

C:\OSGeo4W\bin>set SAGA=C:/OSGeo4W/apps\saga

C:\OSGeo4W\bin>set SAGA_MLB=C:/OSGeo4W/apps\saga\modules

C:\OSGeo4W\bin>PATH=C:\OSGeo4W\apps\Python27\lib\site-packages\Shapely-1.2.18-py2.7-win32.egg\shapely\DLLs;C:\OSGeo4W\apps\Python27\DLLs;C:\OSGeo4W\apps\qgis\bin;C:\OSGeo4W\bin;C:\Windows\system32;C:\Windows;C:\Windows\WBem;C:\OSGeo4W\apps\msys\bin;C:\OSGeo4W\apps\Python27\Scripts;C:/OSGeo4W/apps\saga;C:/OSGeo4W/apps\saga\modules

C:\OSGeo4W\bin>saga_cmd grid_calculus "Grid Volume" -GRID "C:\Users\xxxxx\AppData\Local\Temp\processingdd38dbc0f5ec434f922835f11ed2d9d0\3ddfa5d81c1744819d54de14d3c7a8f1\DTMdiscarica.sgrd" -METHOD 0 -LEVEL 0
ERROR 1: Can't load requested DLL: C:\OSGeo4W\apps\saga\dll\gdal_MrSID.dll
127: Impossibile trovare la procedura specificata.


ERROR 1: Can't load requested DLL: C:\OSGeo4W\apps\saga\dll\gdal_MrSID.dll
127: Impossibile trovare la procedura specificata.


_____________________________________________

##### ## ##### ##
### ### ## ###
### # ## ## #### # ##
### ##### ## # #####
##### # ## ##### # ##
_____________________________________________

_____________________________________________
library path: C:\OSGeo4W\apps\saga\modules\grid_calculus.dll
library name: Grid - Calculus
tool name : Grid Volume
author : (c) 2005 by O.Conrad
_____________________________________________

Load grid: C:\Users\xxxxx\AppData\Local\Temp\processingdd38dbc0f5ec434f922835f11ed2d9d0\3ddfa5d81c1744819d54de14d3c7a8f1\DTMdiscarica.sgrd...




Parameters


Grid system: 1; 1290x 1792y; 624079.089172x 4919509.290207y
Grid: DTMdiscarica
Method: Count Only Above Base Level
Base Level: 0.000000



Grid Volume: Volume: 890177920.097229

C:\OSGeo4W\bin>exit
Converting outputs
Loading resulting layers
Algorithm Raster volume finished

So, I get Volume: 890177920.097229 (I think it's expressed in the project units).


EDIT Before running the algorithm, remember to check this option from Processing > Options:

enter image description here

Otherwise, you won't see any result.

  • I've got the same version but no result is returned :/ – Mirko Feb 19 '17 at 16:04
  • Your dtm didn't have a crs, so I set it manually (EPSG:32632) but I think it's not related to your issue. – mgri Feb 19 '17 at 16:08
  • I managed to estimate the volume value using GRASS r.volume which is slightly different form SAGA Raster Volume. Anyway the result I get is: 890202598.00. Still no idea why I can't get it work.. :/ – Mirko Feb 19 '17 at 16:44
  • @Mirko any news? Did you read the edit on my answer? – mgri Apr 26 '17 at 21:37
1

2017-03-03T21:00:43 0 SAGA execution commands io_gdal 0 -TRANSFORM 1 -INTERPOL 0 -GRIDS "/var/folders/gj/24tjnl3d5q1cbmf8qrzp5l080000gp/T/processing09437b37ce8c4b63aa9d22ecc2283762/60392e4a6d024cc8b128269b081be2cc/DTMdiscaricacopia.sgrd" -FILES "/Users/macbook/Desktop/DTMdiscarica copia.asc" grid_calculus "Grid Volume" -GRID "/var/folders/gj/24tjnl3d5q1cbmf8qrzp5l080000gp/T/processing09437b37ce8c4b63aa9d22ecc2283762/60392e4a6d024cc8b128269b081be2cc/DTMdiscaricacopia.sgrd" -METHOD 0 -LEVEL 0 2017-03-03T21:01:01 0 Risultato della console di esecuzione di SAGA ____________________________

        #####   ##   #####    ##
        ###     ###  ##       ###
        ###   # ## ##  #### # ##
        ### ##### ##    # #####
        ##### #   ##  ##### #   ##
        ____________________________

        SAGA Version: 2.2.3

        ____________________________
        library path:   /Applications/QGIS.app/Contents/MacOS/lib/saga/
        library name:   libio_gdal
        library     :   GDAL/OGR
        tool        :   Import Raster
        author      :   O.Conrad (c) 2007 (A.Ringeler)
        ____________________________



        Parameters


        Grids: No objects
        Files: "/Users/macbook/Desktop/DTMdiscarica copia.asc"
        Transformation: yes
        Interpolation: Nearest Neighbor


        loading: /Users/macbook/Desktop/DTMdiscarica copia.asc



        Driver: AAIGrid

        Bands: 1

        Rows: 1290

        Columns: 1792



        Transformation:

        x' = 624078.589172 + x * 1.000000 + y * 0.000000

        y' = 4921300.790207 + x * 0.000000 + y * -1.000000


        loading band [1/1]




        ____________________________

        #####   ##   #####    ##
        ###     ###  ##       ###
        ###   # ## ##  #### # ##
        ### ##### ##    # #####
        ##### #   ##  ##### #   ##
        ____________________________

        SAGA Version: 2.2.3

        ____________________________
        library path:   /Applications/QGIS.app/Contents/MacOS/lib/saga/
        library name:   libgrid_calculus
        library     :   Calculus
        tool        :   Grid Volume
        author      :   (c) 2005 by O.Conrad
        ____________________________

        Load grid: /var/folders/gj/24tjnl3d5q1cbmf8qrzp5l080000gp/T/processing09437b37ce8c4b63aa9d22ecc2283762/60392e4a6d024cc8b128269b081be2cc/DTMdiscaricacopia.sgrd...




        Parameters


        Grid system: 1; 1290x 1792y; 624079.089172x 4919509.290207y
        Grid: DTMdiscaricacopia
        Method: Count Only Above Base Level
        Base Level: 0.000000



        **Grid Volume: Volume: 890177920.097229**

It was a classical path error: copying and pasting the .asc in the desktop does the job perfectly fine! I think the path to the file was to long or maybe there are some blank spaces in the folders names.

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